1. Field of the Invention
The present invention relates to a deflection yoke, which is mounted on a funnel of a cathode-ray tube, for deflecting an electron beam in a horizontal direction and a vertical direction. The present invention also relates to a cathode-ray tube apparatus with the deflection yoke mounted thereon.
2. Description of the Related Art
A schematic configuration of a conventional deflection yoke (for example, see JP4(1992)-308634A) will be described with reference to FIG. 6. In FIG. 6, a Z-axis is a tube axis of a cathode-ray tube on which a deflection yoke 100 is mounted. The cross-sectional shape of the deflection yoke 100 is substantially symmetrical with respect to the Z-axis. Therefore, FIG. 6 shows a partial cross-sectional view of the deflection yoke 100 on one side with respect to the Z-axis.
Reference numeral 11 denotes a saddle-type horizontal deflection coil, 12 denotes a vertical deflection coil wound around a ferrite core 14 in a toroidal shape, and 13 denotes an insulating frame made of resin for insulating the horizontal deflection coil 11 from the vertical deflection coil 12. Reference numeral 20 denotes a plate-shaped deflection adjusting plate made of a magnetic material, for correcting a magnetic field generated by the horizontal deflection coil 11 and the vertical deflection coil 12.
The deflection adjusting plate 20 is attached to be fixed to a predetermined position on an outer circumferential surface of the insulating frame 13 with an acetate tape 29 having a size larger than that of the deflection adjusting plate 20. At this time, one surface of the deflection adjusting plate 20 comes into direct contact with the outer circumferential surface of the insulating frame 13, and the other surface thereof is covered with the acetate tape 29. After the deflection adjusting plate 20 is attached to the outer circumferential surface of the insulating frame 13, an integrated body of the vertical deflection coil 12 and the ferrite core 14 is mounted so as to cover the insulating frame 13. Thereafter, a hot-melt adhesive 25 is injected into a space between the integrated body of the vertical deflection coil 12 and the ferrite core 14, and the insulating frame 13. The ferrite core 14 and the insulating frame 13 are integrated with each other with the hot-melt adhesive 25.
When a deflection current is supplied to the horizontal deflection coil 11 and the vertical deflection coil 12 of the deflection yoke 100, the deflection adjusting plate 20 vibrates in accordance with an alternating magnetic field generated by the horizontal deflection coil 11 and the vertical deflection coil 12.
In the conventional deflection yoke 100 shown in FIG. 6, the hot-melt adhesive 25 is of a quick drying type. Therefore, the hot-melt adhesive 25 is cured before spreading sufficiently to an entire region of the space between the ferrite core 14 and the insulating frame 13. Thus, a gap may be formed between the acetate tape 29 and the hot-melt adhesive 25. In this state, the force of binding the deflection adjusting plate 20 is relatively weak, so that the deflection adjusting plate 20 bumps into the insulating frame 13 and the hot-melt adhesive 25, both of which have a high hardness, due to the vibration of the deflection adjusting plate 20, thereby causing noise.